• International Journal of Automotive Technology
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• 제7권4호
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• pp.407-413
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• 2006

The liquefied petroleum gas(LPG), mixture of propane and butane, has the potential to reduce toxic hydrocarbon emissions and inhibit ozone formation due to its chemical composition. Conventional mixer systems, however, have problems in meeting the future lower emission standards because of the difficulty in controlling air-fuel ratio precisely according to mileage tar accumulation. Liquid Phase LPG injection(LPLi) system has several advantages in more precise fuel metering and higher engine performance than those of the conventional mixer type. On the other hands, leakage problem of LPLi system at the injector tip is a main obstacle for meeting more stringent future emission regulations because these phenomena might cause excessive amount of THC emission during cold and hot restart phase. The main focus of this paper is the development of a leaked fuel recirculation system, which can eliminate the leaked fuel at the intake system with the activated carbon canister. Leaked fuel level was evaluated by using a fast response THC analyzer and gas chromatography. The result shows that THC concentration during cold and hot restart stage decreases by over 60%, and recirculation system is an effective method to meet the SULEV standard of the LPLi engine.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.7-8
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• 2006

As a new type of flame, tubular flame has attracted much attention from a fundamental viewpoint and many experimental and theoretical studies have been made on its characteristics. Recently, it is also recognized that the tubular flame has great potentials as practical combustor because its stability range is very wide in fuel concentration and also in injection velocity. Thus, tubular flame burners have been developed for various kinds of fuels. They are gaseous fuels of methane, propane, hydrogen, and by-product fuels gases in steel making processes including BFG (Blast Furnace Gas), LDG (LD Converter Gas), and COG (Cokes-Oven Gas), liquid fuels of kerosene, A-type and C-type heavy oils, and a solid fuel of biomass powder. In this paper, recent developments of the tubular flame burners have been briefly introduced.

• 한국수소및신에너지학회논문집
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• 제15권2호
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• pp.129-136
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• 2004

환경문제와 석유자원의 고갈이 많은 연구자들을 기존 탄화수소연료를 대체할수 있는 재생 가능한 연료를 구하는데 많은 노력을 기울이고 있다. 수소연료는 유해배기물질이 없는 연소와 또한 연소후에 재생 가능한 물성분만 배출하는 속성으로 미래의 청정에너지로 각광을 받고 있다. 이러한 이유로 수소연료는 수송기계의 연료로도 주목을 받고 있다. 따라서 수소연료기관 개발은 21세기에도 지속적으로 진행될 것이다. 이에대한 초기연구로 기체 LPG 연료가 아닌 액체 LPG 연료를 흡기관에 분사하여 기화된 LPG 연료를 엔진으로 흡입하는 LPi엔진에 수소연료를 과급하여 엔진에 성능을 연구하고자 하였다.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.77-84
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• 2002

For the purpose of obtaining a fundamental data which is needed to develope the port injection type charged LPLi engine system, we manufactured intake port injection system of liquid charging LPG and modified heavy duty single cylinder LPLi engine from heavy duty diesel engine. Engine output and emission characteristics were analyzed under variable air/fuel ratio and charging pressure. Since LPG is consisted of propane and butane, we investigated combustion characteristics using this two kinds of fuel. From the result of charging engine performance test, engine torque increase about 30% ∼ 40% with 0.3bar charging pressure. In low speed condition, as charging pressure increase, combustion stability improve ill lean bum condition, but, in high speed condition, combustion stability make worse in lean bum condition. We know that engine output decreased rapidly from the condition of air excess ratio 1.3. In addition, we measured emission characteristics under the lean bum and charging condition. From this experiment, we found that CO emission is out of the question in the range from stiochiometric to lean burn and charging condition, but charging pressure has influence on HC emission.

• 한국수소및신에너지학회논문집
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• 제13권4호
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• pp.297-303
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• 2002

The purpose of study is obtaining low-emission and high-efficiency in LPi engine with hydrogen enrichment. The test engine was named variable compression ratio single cylinder engine (VACRE). The fuel supply system provides LPG/hydrogen mixtures based on same heating value. A varied sensors such as crank shaft position sensor (CPS) and hall sensor supplies spark timing data to ignition controller. Displacement of VACRE is $1858.2cm^3$. VACRE was runned 1400rpm with compression ratio 8. Spark timing was set MBT without knocking. Relative air-fuel ratio($\lambda$) of this work was varied between 0,8 and 1.5.

• Journal of Advanced Marine Engineering and Technology
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• 제35권5호
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• pp.566-575
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• 2011

LPG 연료공급방식은 배출가스를 저감시킬 수 있는 유용한 시스템으로 연구가 지속적으로 진행되고 있다. LPG는 경유와 휘발유보다 높은 증기압과 낮은 점도와 표면장력을 유지하므로 고무류와 화학 반응에 따른 연료펌프의 기계적인 손상으로 내구성이 저하되고 있는 실정이다. 본 연구에서는 이러한 문제점을 해결하기 위해 LPLi 시스템에서 유지보수의 편리함과 가격경쟁을 위해 개발된 외장형 펌프를 사용하여 LPG 연료의 조성 및 온도에 따른 특성을 평가하고자 실험을 하였다. 그 결과로서, 내장형 펌프와 외장형 펌프의 성능차이는 거의 없으며 프로판 함유율이 높고, 연료온도가 높아짐에 따라 유량은 많아지나 펌프효율은 거의 차이가 없었다. 또한 LPG 자동차 연료공급장치의 특성상 연료조성 및 온도변화에 따른 차압도 거의 일정하게 나타내었다.